implemented aligned notes

gallery/notes.typ

@@ -74,10 +74,19 @@
 #chronos.diagram({
   _par("a", display-name: "Alice")
   _par("b", display-name: "Bob")
+  _par("c", display-name: "Charlie")
+  _par("d", display-name: "Donald")
+  _par("e", display-name: "Eddie")
 
   _note("over", [initial state of Alice], pos: "a")
-  _note("over", [initial state of Bob], pos: "b", aligned: true)
+  _note("over", [initial state of Bob the builder], pos: "b", aligned: true)
-  _seq("b", "a", comment: [hello])
+
+  _note("over", [Note 1], pos: "a")
+  _note("over", [Note 2], pos: "b", aligned: true)
+  _note("over", [Note 3], pos: "c", aligned: true)
+
+  _seq("a", "d")
+  _note("over", [this is an extremely long note], pos: ("d", "e"))
 })
 
 #pagebreak()
@@ -112,3 +121,18 @@
     #underline([This is hosted], stroke: rgb("#FF33FF")) by #box(baseline: 50%, image("gitea.png", width: 1cm, height: 1cm, fit: "contain"))
   ], pos: ("a", "b"))
 })
+
+// TODO
+/*
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: [Alice])
+  _par("b", display-name: [Bob])
+
+  _seq("a", "b", comment: [Hello])
+  _note("left", [This is a note])
+
+  _seq("[", "a", comment: [Test])
+  _note("left", [This is also a note])
+})*/

src/diagram.typ

@@ -58,6 +58,7 @@
   // List participants
   let linked = ()
   let last-seq = none
+  let last-note = none
   for (i, elmt) in elmts.enumerate() {
     if elmt.type == "par" {
       participants.push(elmt)
@@ -107,12 +108,21 @@
         seq.insert("linked-note", elmt)
         elmts.at(last-seq.i) = seq
       }
+      if elmt.aligned {
+        let n = last-note.elmt
+        n.aligned-with = elmt
+        elmts.at(last-note.i) = n
+      }
       elmts.at(i) = elmt
       if elmt.side == "left" {
         linked.push("[")
       } else if elmt.side == "right" {
         linked.push("]")
       }
+      last-note = (
+        elmt: elmt,
+        i: i
+      )
     }
   }
   linked = linked.dedup()

src/note.typ

@@ -15,6 +15,16 @@
 )
 
 #let _note(side, content, pos: none, color: COL-NOTE, shape: "default", aligned: false) = {
+  if side == "over" {
+    if pos == none {
+      panic("Pos cannot be none with side 'over'")
+    }
+  }
+  if aligned {
+    if side != "over" {
+      panic("Aligned notes can only be over a participant (got side '" + side + "')")
+    }
+  }
   return ((
     type: "note",
     side: side,
@@ -22,7 +32,8 @@
     pos: pos,
     color: color,
     shape: shape,
-    aligned: aligned
+    aligned: aligned,
+    aligned-with: none
   ),)
 }
 
@@ -66,7 +77,7 @@
   if note.side == "over" {
     if type(note.pos) == array {
       let xs = note.pos.map(par => x-pos.at(pars-i.at(par)))
-      return xs.sum() / xs.len()
+      return (calc.min(..xs) + calc.max(..xs)) / 2
     }
   }
   return x-pos.at(pars-i.at(note.pos))
@@ -162,7 +173,7 @@
     anchor: "center"
   )
 
-  if note.pos != none or note.side == "across" {
+  if note.aligned-with == none and (note.pos != none or note.side == "across") {
     y -= h
   }
 

src/renderer.typ

@@ -65,23 +65,36 @@
     
     } else if elmt.type == "note" {
       let (p1, p2) = (none, none)
+      let cell = none
       if elmt.side == "left" {
         p1 = "["
         p2 = elmt.pos
+        cell = get-note-box(elmt)
       } else if elmt.side == "right" {
         p1 = elmt.pos
         p2 = "]"
+        cell = get-note-box(elmt)
+      } else if elmt.side == "over" {
+        if elmt.aligned-with != none {
+          let box1 = get-note-box(elmt)
+          let box2 = get-note-box(elmt.aligned-with)
+          let m1 = measure(box1)
+          let m2 = measure(box2)
+          cell = box(width: (m1.width + m2.width) / 2, height: calc.max(m1.height, m2.height))
+          p1 = elmt.pos
+          p2 = elmt.aligned-with.pos
+        }
       }
 
-      if p1 != none and p2 != none {
+      if p1 != none and p2 != none and cell != none {
         let i1 = pars-i.at(p1)
         let i2 = pars-i.at(p2)
         cells.push(
           (
             elmt: elmt,
-            i1: i1,
+            i1: calc.min(i1, i2),
-            i2: i2,
+            i2: calc.max(i1, i2),
-            cell: get-note-box(elmt)
+            cell: cell
           )
         )
       }
@@ -101,6 +114,28 @@
     widths.push(w1 / 2pt + w2 / 2pt + PAR-SPACE)
   }
 
+  // Compute minimum width for over notes
+  for n in elements.filter(e => (e.type == "note" and
+                                 e.side == "over" and 
+                                 type(e.pos) == str)) {
+    
+    let m = note.get-size(n)
+    let i = pars-i.at(n.pos)
+
+    if i < widths.len() {
+      widths.at(i) = calc.max(
+        widths.at(i),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+    if i > 0 {
+      widths.at(i - 1) = calc.max(
+        widths.at(i - 1),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+  }
+
   // Compute minimum width for simple sequences (spanning 1 column)
   for cell in cells.filter(c => c.i2 - c.i1 == 1) {
     let m = measure(cell.cell)
@@ -111,7 +146,7 @@
   }
 
   // Compute minimum width for self sequences
-  for cell in cells.filter(c => c.i1 == c.i2) {
+  for cell in cells.filter(c => c.elmt.type == "seq" and c.i1 == c.i2) {
     let m = measure(cell.cell)
     let i = cell.i1
     if cell.elmt.flip {
@@ -252,7 +287,9 @@
     // Note
     } else if elmt.type == "note" {
       if not elmt.linked {
-        y -= Y-SPACE
+        if not elmt.aligned {
+          y -= Y-SPACE
+        }
         let shps
         (y, shps) = draw-note(elmt, y, lifelines)
         shapes += shps